The invention relates to an oil atomizer. In another aspect, the invention relates to atomizing an oil. In yet another aspect, the invention relates to atomizing an oil feed for a catalytic cracking unit.
In a fluid catalytic cracking process, it is important that the oil be vaporized prior to its contact with the catalyst to avoid excessive coke formation. Usually, the oil is sprayed into contact with the catalyst in a transfer line or riser-reactor and the radiant heat from the cracking catalyst vaporizes the oil droplets. With heavier, higher boiling feedstocks, this method of vaporizing the feedstock is not entirely satisfactory. Heavy oils, such as heavy cycle oils and vacuum residuums are difficult to completely vaporize prior to contacting with with the catalyst. Heavy reliance on radiant heat to vaporize the feedstock thus does not always provide acceptable results.
Steam is frequently used to assist in dissociation of the oil feedstock. However, the use of steam in a catalytic cracking unit can quickly become quite expensive because of the amounts involved. Also, large amounts of steam deactivate the cracking catalyst and change conditions in the riser-reactor. It would be very desirable to avoid the use of large amounts of steam for feedstock dissociation in a cracking unit if possible.